1. Field of the Invention
This invention pertains to a flooring system and in particular to a flooring system having removable and replaceable flooring panels, such a system commonly being called an access floor.
2. Discussion of the Background
One of the advantages of access floors is that the panels are removable, either singly or in groups. Because such floors are typically manufactured of prefabricated, mass-produced panels, it is desirable that any one or more of the panels be replaceable by any other panel of the same type (i.e., by any geometrically similar panel), whether or not the replacement panel was originally a part of the access floor and whether or not the replacement panel was manufactured in the same lot as the original panels.
For example, it is desirable to be able to replace a damaged panel with a more recently manufactured panel. Also, whenever several adjacent panels of the same nominal size have been removed simultaneously, it is desirable for ease of replacement that these panels be replaceable in an arbitrary configuration according to which it is not necessary to replace each panel in the precise location from which it was removed. Similarly, it is desirable to be able to replace a large number of original panels with replacement panels that are not original.
As a natural consequence of manufacturing, a typical group of flooring panels might be manufactured to a particular set of nominal dimensions, but the actual dimensions of each individual panel will vary within ranges of manufacturing tolerance. Such a variation in actual dimensions will be present among the panels of an access floor when it is initially installed. Replacement panels, such as those purchased later from the same manufacturer, also will exhibit ranges of tolerance about the nominal dimensions.
In recognition of such dimensional variations and the desirability of the interchangeability of panels, it has been the practice in the industry to install an access floor in two steps. The first step involves laying out a gridding on the sub-floor to be covered. The gridding is typically established by making measurements along the floor and placing marks on the floor to establish a system of points and lines designating where the panels will be placed. The second step in installing the access floor is the step of actually placing the panels in their final locations, together with any pedestals on which the panels are to rest.
The gridding, laid out in advance, typically is based upon the worst-case assumption that every panel that will be installed initially has actual dimensions at the maximum negative values of the manufacturing tolerances, and that every replacement panel that may later be installed will have actual dimensions at the maximum positive values of the tolerance ranges. When the actual flooring panels are installed according to this gridding, there typically will be gaps between adjacent panels, and the size of the gap will vary with the actual dimensions of contiguous panels, as installed.
It is widely recognized that such gaps between panels should be minimized to the extent that it is possible to do so and still allow for interchangeability of the panels. However, within the scope of this teaching, some desire to provide a minimum possible gap between panels of essentially zero while others prefer to have a guaranteed finite gap of, for example, about 0.010 inches. The reason that some desire to have a guaranteed minimum non-zero gap is that panels which touch each other can produce squeaking when someone walks across the floor. Such a minimum possible gap, whether essentially zero or some predetermined finite value, may be thought of as a minimum desired gap, depending upon preference.